Finned electric air heater



Dec. 7, 1948-. E. R. WALTON I 3 3 FINNED ELECTRIC AIR HEATER Filed Jan. 18, 1946 2 Shets-Sheet l id- WM Patented Dec. 7, 1948 FINNED ELEGTRIQAIR HEATER" ErnestlR Walton, Seattle Application January 18, 1946p SeriaiNo; 641L919 Claims,

This; invention. relates to a. finned electric air heaterand an. object oflthis invention is to provide an electric heater or simple and durable construction; that is highly efficient in heating circulating air.

Another object is to providea cast metal electric, heating unit. that has an. electric heating element embedded; therein when the unit iscast to thereby provide a close contact between the heating element and the metal of the heating unit that. heat, generated; by the, heating. element will, be rapidly transferred to; the metalheating unit. andoyerheatingoi; the element. will bev prevented;

Another object is. tolprovtide simple and efficient heating units that may be used in multiple: to build up an electric. heating plant of. any desired capacity depending on number of units that are used and to further provide heating. units to which the, supply-of electriccurrent may be individually controlled irrespective of the number oi units inan assembly.

Another'object is toprovid-e an electric heating unit: having a centrally-positioned e1ement.carrying portion within; which an electric. heating element embedded andhaving a plurality of thin, flat, spaced apart heat radiating. fins. extending outwardly from said central portion in planes substantially Parallel to the axis of the imit, saidfins providing: ample heat radiating surface to-transfer heatto'the; air fast enough so that the element carryingportion of the heating unit; can operate at; a; relatively low temperature.

Another 0b-.1Ct -i$r t@ provide an electric heating unit of one piC&meta1:COIlSt1fuQtl0n and ofconcavoeconvexshape havingan electric heating element embeddedin itsicentral portion and having a. ..peripheral portionformed of thin flat spaced apart radial fins that are inclined toward the.

direction fromwhich-the air approac es the heat ing unit, said fins afiording a: lar e area of heat.

tionand the body portion through whichair may move: upwardly and inso. doing pick up heat from the central portion oftheheati-ng unit Another obicct of th'einvention will be apparentfromt e followingdescription taken in connection with the accompanyingdrawings.

In thedrawings Figure l is a top planviewofan electric heating unit: constructed in accordancewith this invention.

- Fig. 2 is a-sectional view ofthe same taken onbroken line 2-4 of Fig; 1a 1 Fig; 3 iso. ton-plan:view-showing a plurality of these electric heating units assembled in superposedarelation. g

4: isa,sectionallview-taken substantially on bro'lrenlirie -4; otiEig'. 3;

Fig. 5'. is a sectional viewshowing an electric heating unit: of modified l for-m;

Like reference numerals designate like parts throughout the several. views.

Figs 1 aHd-ZlShOW aDJ-GIEGtrlC heating unit-constructed? in:-' accordance with this invention comprising' an hub portior'r- 10-- connected byintegral web'members it with arr annular element carryportion [21. thatv hasoutwardly projecting spaced" apart heat radiating vanes or fins l3; Passageways lllsthrough -which air-may pass upwardly/are. provided between-the hub portion l0 amt the annular body portion I 21. Preferably-heat" radiatingmembers J 5oi thin metal bent into corrugated shapeare provided in the passageways to the-air: andthus help tomaintai'n a relativelylow operating temperature of'theheating unit.

Three; heat'zradiating-mem-bers l5 are shown but obviously a greater or less number of said members" may-be used.

Anelectric heating element Hi of Calrod type is embedded in the annular element carrying portion Hiat'the-timeof casting and the terminal portions of: this: heating element Ill extend" outwardly to. the periphery of the heating unit through an arm ll: of" solid metal to a location Where they may be easily connected'with circuit wires. The CaltodP- type element Hi is in the nature ofza metal tube having therein a high resistance conductorthat is insulated from the tube. Preferably the portionof the' electric element. 1.6 that is "embedded within the annular element carryingsrr'iernber i2 is inthe form of a helical coil as: indicated in the drawings Theiheatingunit formed by parts In; H, I! and lawisori concauo-convex shape andin operation the air to be heated is caused to first contact the concave side of the unit. For instance, when the heating unit is mounted in a substantially hori- Zontal position with its concave side downward and its axis substantially vertical then the air 'will be caused to pass upwardly through said heating unit.

Due to the generally concave shape of the lower side of the heating unit and due to the downward slope of the fins l3 the upwardly moving air will not only pass between the fins I3 but some of this air will be converged toward the center of the heating unit and will pass upwardly through and around the element carrying portion l2, which is the most highly heated portion of the unit, and through the passageways M. This will help to keep the element carrying portion 12 and element H5 at a relatively low and safe operating temperature.

In, constructing a furnace for the heating of air, used for instance in heating a home or a building, a number of these heating units are preferably supported one above another in vertically spaced apart relation by spacer tubes I8. The lowermost tube l8 can be used to support the assembly or said assembly can be supported by other means. When thus supported the sev-- eral heating units are preferably connected together by means, such as an axially positioned rod 19 that passes through holes 20 in the hubs i6 and through the tubes 18. Preferably the hubs ID are made with bosses to fit within the ends of the tubes l8.

When a plurality of heating units are assembled asshown in Figs. 3 and 4 alternate units are preferably angularly offset enough so that the fins l3 of each unit will be in line with the spaces between fins of adjacent units.

, Any suitable housing may be provided around the assembled heating units and air is caused to move upwardly through and past the heating units. The heating elements i6, being cast into each heating unit have very close contact with the metal of the unit and the heat is conducted away from the element very rapidly. The heat radiating fins l3 provide a very large heat radiating'surface over which the air is constantly passing. Thus the heat given off by the heating elements will be picked up very quickly by the circulating air and the heating elements will not become over heated. The generally concave shape of the lower sides of the heating units will constantly tend to converge the upwardly moving air toward the center of the units thus efficiently picking up heat from the center portions of the units and keeping these center portions of the units at a relatively low temperature;

The heating unit shown in Fig. 5 comprises a central body portion 2| having centrally positioned downwardly projecting integral hub 22 and having a centrally positioned recess 23 on its upper side. The hubs 22 serve as spacers when a plurality of the units shown in Fig. 5 are assembled one aboveanother and the end of each hub except the lowermost one in the assembly 22 rests in the recess 23 of the heating unit next below it. An axial passageway 24 is provided in parts 2| and 22 for an assembly rod similar to the rod l9 of Fig. 4.

, The heating unit of Fig. 5 is of concavo-convex shape similar to the units shown in Figs. 1 to 4 and has radial fins 25 and a heating element 25 similar to the fins l3 and heating elements 16 of Figs. 1 to 4. The heating unit of Fig. 5 func- 4 tions similarly to the heating units of Figs. 1 to 4 except that no centrally positioned air passageways corresponding to passageways l4 are provided in the Fig. 5, structure and the converged air, after contacting the hub 22 and bottom surface of central body portion 2|, will pass outwardly around the body portion 2! and upwardly between the fins 26. This will keep the body portion 2! at a relatively low or safe working temperature.

The foregoing description and accompanying drawings clearly disclose preferred embodiments of my invention but it will be understood that changes in the same may be made Within the scope and spirit of the following claims.

I claim.

1. A one piece cast metal electric heating unit of relatively fiat circular concavo-convex shape, comprising a centrally positioned element carrying portion; an electric heating element embedded in said element carrying portion; and thin fiat spaced apart heat radiating fins extending outwardly from said element carrying portion in planes substantially parallel to the axis of aid unit and in directions conforming to the concavo-convex shape of said unit, whereby an umbrella shaped finned structure is provided so that air directed against the concave side of said unit will be converged toward the axis thereof.

2. A one piece cast metal electric heating unit of relatively fiat circular concavo-convex shape supported in a substantially horizontal plane with its axis substantially vertical, comprising a centrally positioned element carrying portion; an electric heating element embedded in said element carrying portion; and thin flat spaced apart heat radiating fins extending outwardly and downwardly from said element carrying portion in substantially vertical planes, said downwardly inclined fins cooperating to form an umbrella shaped unit which tends to converge ascending air toward said element carrying portion and said fins providing a relatively great heat radiating surface exposed to ascending air.

3. A one piece cast metal electric heating unit of relatively fiat circular concave-convex shape, comprising a concentrically positioned annular element carrying portion; a hub positioned centrally of said element carrying portion; air passageways extending through said element carrying portion around said hub; an electric heating element embedded in said element carrying portion; and thin flat spaced apart heat radiating fins extending outwardly from said element carrying portion in planes substantially parallel to the axis of said unit and in directions conforming to the concavo-convex shape of said unit, said inclined fins cooperating to provide an umbrella shaped structure which tends to converge air that is directed against the concave side of said unit.

4. A cast metal electric heating unit of relatively flat circular concavo-convex shape, comprising anannular element carrying portion; a hub positioned centrally of said element carrying portion; integral webs connecting said element carrying portion and said hub and cooperating therewith to provide air passageways extending through said unit around said hub; separable heat radiating metal members of corrugated shape positioned in said passageways in heat exchanging contact with said element carrying portion; an electric heating element embedded in said element carrying portion; and thin flat tively flat circular concave-convex shape, each 10 having a centrally positioned element carrying portion, an electric heating element embedded in said element carrying portion and thin flat spaced apart heat radiating fins extending outwardly from said element carrying portion in planes substantially parallel to the axis of said unit; and centrally positioned upright spacer means supporting said heating units one above 6 another in vertically spaced apart relation, the concavo-convex shape of said finned units contributing to the stability of the structure and tending to converge air toward the center thereof.

ERNEST R. WALTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,879,019 Ballentine Sept. 27, 1932 1,879,889 Ballentine Sept. 27, 1932 2,109,279 Soverhill Feb. 22, 1938 2,158,602 Calhoun May 16, 1939 

